I've been told, many times, that the word "polyamory" is not really necessary, as it's simply a synonym for "open relationship" or "swinging" (or, depending on the person talking to me, "cheating"). This idea seems to assume that there's really only one kind of non-monogamy, which is kind of silly.

I started thinking lately about the various ways in which a relationship can be non-monogamous, and the intersections between different sorts of non-monogamy, and after tinkering around with the notion for a while I've come up with this diagram.

A relationship can be non-monogamous without being open; cheating relationships, polyfidelitous relationships, and religious polygyny are all examples. I've made polyamory and swinging separate and nonoverlapping here, though of course a person can be polyamorous and also be a swinger (they're two different behaviors engaged in by the same person, just as a person can be a swinger and also be a cheater, and so on).

BDSM throws a monkeywrench into the issue because there are so many ways that people involved in BDSM can be non-monogamous. I've seen people who play at play parties with other folks but don't do so outside play parties and don't form relationships; that sort of arrangement overlaps with swinging. I've seen various flavors of polyamorous and polyfi BDSM relationships. I've seen closed-group non-monogamy that isn't quite polyamory and looks more like closed-group swinging, though God knows there's some overlap between closed-group swinging and polyfi; I've known closed group swingers whose groups stay stable for longer than most marriages do. And there's a sliver of non-monogamous BDSM relationships that don't intersect with anything else; "I'll arrange a gang bang for you and you'll LIKE IT," ferinstance.

And then there's con sex, which overlaps with a whole lot of other stuff. But someone could probably write an entire book about con sex. And now that I think about it, I'd probably read it.

"Hundred mile rules" or "hundred mile agreements" are relationship agreements, sometimes tacit, that say that when one member of a couple is out of town (on business trips, or on military deployment, or whatever), it's OK to get some nookie on the side, as long as it doesn't come back when the person returns home.

Soft swinging is the practice of going to public venues for sex (swing clubs, play parties, and so on), but only having sex with your partner, not with other people there.

Seems like that could fit into a lot of places -- I'd still call that an open relationship, it just has pretty specific boundaries; or it could be a closed poly relationship that hasn't found a third yet, right?

I've made polyamory and swinging separate and nonoverlapping here, though of course a person can be polyamorous and also be a swingerThe general consensus of poly people seems to be that casual sex between close friends is polyamory. The general consensus of swingers seems to be that casual sex between close friends is swinging.I do identify as both poly and a swinger, and I suspect poly people just accept it as poly because they don't disapprove of it.

I do think casual sex without ruling out progressing to serious relationships is a clear area of overlap, though.

Great! But you know what's missing? Scale. The area of the shapes should represent how common the relationships are. For example, from what I understand, DADT is way more commonly found than polyamory, but it's not reflected in this graph.

Is it even true, btw? I know we don't yet have serious research and stats, but even your hunch would be very valuable, I think. You meet a lot of people in various open relationships.

@skittenwench: in my experience, DADT lends itself more to 100-mile-rule type arrangements and less to polyfidelity. It's rare to find a set of people who are both DADT and in multiple longer-term-committed relationships. But cheating is a different thing entirely; consent is the tipping point. When partners don't want to know/think about their partners' otherloves, those relationships aren't supported in the context of the primary, and may even require lying in the primary context to maintain the DT agreement. It's unusual for that to be a sustainable arrangement, so if DADT persists, the outside dalliances rarely can.

I consider myself both poly and a swinger.Have lived in a triad (long term) currently date in a quad situation and off and on we play in swingers circles and hit the party scene.Currently we (4 of us) are just sticking to eachother, but it will most likely go back to swinging when spring is in the air.

The funny thing is that because I swing and self label as poly I get to know a lot of people from both camps.Ive met poly people that have way more casual sex than many swingers and swingers that need a much stronger connection with sex partners than many who call themselves poly.

I've had that same experience as well--both in meeting poly folks who really like casual sex, and in meeting swingers who require a level of non-sexual connection in order to have sex with people. The newest version of the map shows an intersection between swinging and poly for just that reason. :)

After eight years in the swing lifestyle, I believe the understanding here of soft swap is not quite correct. Generally, soft swap means swapping partners for sexual play that includes everything except for penis/vaginal penetration. Pleasuring to orgasm with your hands, fingers, tongue and lips are all part of it.